Irradiation inactivates lymphocytes present in blood products, which may cause transfusion-associated graft-versus-host disease (Ta-GVHD). Ta-GVHD is a fatal and exceedingly rare complication of transfusion that occurs when transfused donor lymphocytes attack the recipient due to recognition of the human leukocyte antigens (HLAs) of the recipient as foreign. Clinical presentation includes an erythematous and pruritic rash, diarrhea, liver enzyme abnormalities, fever, and pancytopenia, typically occurring 8 to 10 days following transfusion. Packed red blood cells (PRBCs) and platelets may be irradiated. Irradiation is obligatory in the case of granulocyte concentrates.
1. Specific products: Directed donations from first- and second-degree relatives, HLA-selected/matched platelets, granulocyte concentrates.
2. Fetal and neonatal indications: Intrauterine transfusion, neonatal exchange transfusions, very low birth weight infants.
3. Congenital severe T-cell immune deficiency, complex congenital cardiac abnormalities.
4. Hodgkin lymphoma (indefinitely).
5. Allogeneic stem cell transplant: From the time of initiation of conditioning chemotherapy and during GVHD prophylaxis and treatment.
6. Autologous stem cell transplant: From the time of initiation of conditioning chemotherapy to 3 months post transplant.
7. Specific medications (indefinitely): Purine analogues, alemtuzumab, antithymocyte globulin (ATG) (only in the context of aplastic anemia).